Odpowiedź :
Odpowiedź:
a)
1/2y+3=7
1/2y = 7 - 3 /*2
y = 4 * 2 = 8
b)
1/7y - 5/7 = 2
1/7y = 2 + 5/7 /*7
y = 7(2 5/7) = 7 * 19/7 = 19
c)
1/4y+3/4=7/4
1/4y = 7/4 - 3/4 /*4
y = 4 * 4/4 = 4
d)
7/9(y+2)=7/9
7/9y + 14/9 = 7/9
7/9y = 7/9 - 14/9 /*9/7
y = 7/9 * 9/7 = 1
e)
2/3(y-1)=2/3
2/3y - 2/3 = 2/3
2/3y = 2/3 + 2/3 /*3/2
y = 4/3 * 3/2 = 2
f)
-5/11(y-4)=5/11
-5/11y + 20/11 = 5/11
-5/11y = 5/11 - 20/11 /*(-11/5)
y = -15/11 * (-11/5) = 3
Szczegółowe wyjaśnienie:
Odpowiedź:
[tex]a)\\\\\frac{1}{2}y+3=7\ \ /\cdot2\\\\y+6=14\\\\y=14-6\\\\y=8\\\\\\b)\\\\\frac{1}{7}y-\frac{5}{7}=2\ \ /\cdot7\\\\y-5=14\\\\y=14+5\\\\y=19\\\\\\c)\\\\\frac{1}{4}y+\frac{3}{4}=\frac{7}{4}\ \ /\cdot4\\\\y+3=7\\\\y=7-3\\\\y=4[/tex]
[tex]d)\\\\\frac{7}{9}(y+2)=\frac{7}{9}\ \ /:\frac{7}{9}\\\\y+2=1\\\\y=1-2\\\\y=-1\\\\\\e)\\\\\frac{2}{3}(y-1)=\frac{2}{3}\ \ /:\frac{2}{3}\\\\y-1=1\\\\y=1+1\\\\y=2\\\\\\f)\\\\-\frac{5}{11}(y-4)=\frac{5}{11}\ \ /:\frac{5}{11}\\\\-(y-4)=1\\\\-y+4=1\\\\-y=1-4\\\\-y=-3\ \ /\cdot(-1)\\\\y=3[/tex]